Method for extracting long-chain dicarboxylic acid from fermentation liquor

Abstract

The invention provides a method for extracting and purifying long-chain dicarboxylic acid from fermentation liquor, which comprises the following steps: (1) controlling the pH value of the fermentation liquor to be less than or equal to 5 and the density to be 0.9-1.16 g / cm < 3 > to obtain a first solid-liquid mixture; (2) centrifuging the first solid-liquid mixture to obtain a second solid-liquid mixture of which the content of long-chain dibasic acid is greater than that of other solid substances and a third solid-liquid mixture of which the content of long-chain dibasic acid is smaller than that of long-chain dibasic acid in the second solid-liquid mixture; and (3) separating the second solid-liquid mixture to obtain the long-chain dicarboxylic acid. The method is simple to operate, low in equipment requirement and investment and high in treatment efficiency. And most thalli and impurities in the fermentation liquor are removed through centrifugal separation. And the obtained product has high purity and high product yield.

Description

[0001] This application is a divisional application. The application number of its parent application is 2020102470420, the application date is March 31, 2020, and the invention title is "A method for extracting long-chain dicarboxylic acids from fermentation broth". Technical Field

[0002] The present invention relates to a method for extracting long-chain dicarboxylic acids from fermentation broth. Background Art

[0003] Long-chain dicarboxylic acids (LCDA), with the general structural formula: HOOC-(CH 2 ) m -COOH (n = 8 - 16), abbreviated as DCn, n = 10 - 18, is an important organic intermediate and is widely used in fields such as chemical engineering, light industry, pesticides, medicine, and new materials. Currently, the most conventional method for preparing long-chain dicarboxylic acids is through fermentation of long-chain alkanes, fatty acids, and fatty acid derivatives by specific bacterial strains.

[0004] Currently, for long-chain dicarboxylic acids prepared by biological fermentation, the production process is relatively complex. The fermentation broth often needs to be subjected to multiple operations such as alkali dissolution, decolorization, and filtration to remove impurities such as cell tissues, proteins, and pigments of fermentation microorganisms, and then the long-chain dicarboxylic acids are crystallized by adding acid. On the one hand, a large amount of alkali and acid need to be consumed, and the salt content in the crystallization mother liquor is too high, and complex post-treatment is required to meet the discharge standards. On the other hand, multiple decolorization and filtration operations will, to a certain extent, extend the production cycle and may also result in a loss of product yield.

[0005] For example, Chinese Patent CN1053470C discloses the following method for preparing long-chain dicarboxylic acids: adding alkali to the fermentation broth of tridecane dicarboxylic acid (DC13) to adjust the pH value to 10 - 12, heating the fermentation broth to 85 - 90 °C to break the emulsion. In some cases, the remaining alkane in the upper layer is recycled, the clarified solution in the middle layer is collected, and the cell layer can be reprocessed to obtain a second clarified solution, or directly centrifuged or filtered. Then, the clarified solution is decolorized with activated carbon at 85 - 90 °C, and the activated carbon is removed. HCl or H 2 SO 4 is further added to the decolorized solution to adjust the pH value to precipitate the dicarboxylic acid crystals, obtaining the long-chain dicarboxylic acid product.

[0006] For a fermentation broth with a pH value of 7 - 8, first, the alkane and cells are removed, and a large amount of alkali is added to the fermentation broth, such as adjusting the pH of the fermentation broth to about pH 10 - 12. After subsequent acidification, an excessive amount of alkali is also used to neutralize the corresponding excessive acid. As a result, excessive salt is produced and discharged into the wastewater.

[0007] For example, a demulsification method is disclosed in Chinese Patent CN104693018A. The fermentation broth of long-chain dibasic acid is directly acidified, that is, the precipitated long-chain dibasic acid and thallus are separated from the fermentation broth, dried, and then the thallus is removed by extraction and purification with an organic solvent. The key problem of this method is that impurities will be dissolved in the organic solvent, resulting in a decrease in the purity and yield of the product. Summary of the Invention

[0008] The present invention provides a method for extracting long-chain dibasic acid from a fermentation broth, and the method includes the following steps:

[0009] (1) Controlling the pH of the fermentation broth ≤ 5 and the density to be 0.9 - 1.16 g / cm 3 to obtain a first solid-liquid mixture;

[0010] (2) Centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture with a long-chain dibasic acid content greater than the content of other solid substances, and a third solid-liquid mixture with a long-chain dibasic acid content less than the long-chain dibasic acid content in the second solid-liquid mixture;

[0011] (3) Separating long-chain dibasic acid from the second solid-liquid mixture.

[0012] Further, the method includes the following steps:

[0013] (1) Controlling the pH of the fermentation broth ≤ 5 and the density to be 0.9 - 1.16 g / cm 3 , and after cooling treatment, obtaining a first solid-liquid mixture, and the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 - 1000 μm;

[0014] (2) Centrifuging the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture with a long-chain dibasic acid content greater than the content of other solid substances, and a third solid-liquid mixture with a long-chain dibasic acid content less than the long-chain dibasic acid content in the second solid-liquid mixture;

[0015] (3) Separating long-chain dibasic acid from the second solid-liquid mixture.

[0016] After centrifugation, most of the long-chain dibasic acid enters the second solid-liquid mixture (i.e., the heavy phase after centrifugation), and most of the thallus enters the third solid-liquid mixture (i.e., the light phase after centrifugation) so as to be separated from the long-chain dibasic acid. The long-chain dibasic acid content (g) in the third solid-liquid mixture is less than the long-chain dibasic acid content (g) in the second solid-liquid mixture.

[0017] According to some embodiments of the present invention, the recovery rate of thallus in the third solid-liquid mixture is 75 - 95%, such as 80wt%, 85wt%, 88wt%, 90wt%.

[0018] For the method described in any one of the present inventions, the content of the long-chain dibasic acid in the second solid-liquid mixture is ≥ 40 wt%, further 40 - 70 wt%, for example, more than 43 wt%, more than 48 wt%, more than 50 wt%, more than 55 wt%, more than 57 wt%, more than 65 wt%.

[0019] For the method described in any one of the present inventions, the equipment for centrifugation includes but is not limited to hydrocyclones, horizontal sedimentation centrifuges, siphon scraper centrifuges, or any combination thereof. The rotational speed for centrifugation is 500 - 5000 rpm, further 1500 - 2900 rpm, for example, 1800 rpm, 2000 rpm, 2500 rpm, 2700 rpm.

[0020] For the method described in any one of the present inventions, the equipment for centrifugation is a horizontal sedimentation centrifuge, and the rotational speed of the centrifuge drum of the horizontal sedimentation centrifuge is 1500 - 4500 rpm, further 1500 - 2900 rpm, for example, 1800 rpm, 2000 rpm, 2500 rpm, 2700 rpm.

[0021] According to some embodiments of the present invention, before the temperature reduction treatment in step (1), the fermentation broth is kept at 92°C - 103°C for 10 - 120 min, further 20 - 120 min, still further 30 - 90 min, still further 50 - 60 min, for example, 20 min, 30 min, 60 min, 90 min, 100 min, 110 min. The temperature for keeping warm is, for example, 94°C, 96°C, 98°C, 100°C, 101°C, 102°C.

[0022] According to some embodiments of the present invention, the method includes the following steps:

[0023] (1) Control the pH of the fermentation broth ≤ 5 and the density is 0.9 - 1.16 g / cm 3 , keep the fermentation broth at 92°C - 103°C for 10 - 120 min, and after the temperature reduction treatment, obtain a first solid-liquid mixture, and the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 - 1000 μm;

[0024] (2) Centrifuge the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture with the content of long-chain dibasic acid greater than the content of other solid substances, and a third solid-liquid mixture with the content of long-chain dibasic acid less than the content of long-chain dibasic acid in the second solid-liquid mixture;

[0025] (3) Separate the long-chain dibasic acid from the second solid-liquid mixture.

[0026] According to some embodiments of the present invention, the density of the fermentation broth in step (1) is 0.95 to 1.12 g / cm 3 , for example, 1.10 g / cm 3 , and further 0.98 to 1.06 g / cm 3 , for example, 0.99 g / cm 3 , 1.00 g / cm 3 , 1.02 g / cm 3 , 1.04 g / cm 3 , 1.05 g / cm 3 . The method for controlling the density of the fermentation broth may be dilution treatment, concentration treatment commonly used in the art, or adding inorganic salts or inorganic salt solutions to the fermentation broth. For example, when the density of the fermentation broth is low, inorganic salts or inorganic salt solutions can be added to increase the density of the fermentation broth. The inorganic salt may be sodium sulfate, for example.

[0027] According to some embodiments of the present invention, in step (1), the concentration of the long-chain dibasic acid in the fermentation broth is controlled to be 5 to 15 wt%, further 6 to 12 wt%, and further 6 to 10 wt%. Before the temperature reduction treatment in step (1), the fermentation broth may or may not be subjected to concentration adjustment to control the concentration of the long-chain dibasic acid in the fermentation broth within the above range. The method for adjusting the concentration may be dilution or concentration treatment commonly used in the art, for example. The concentration of the long-chain dibasic acid in the fermentation broth may be adjusted before the start of step (1) or at any stage of step (1). For example, after controlling the pH of the fermentation broth, the concentration of the fermentation broth is adjusted.

[0028] According to some embodiments of the present invention, the method includes the following steps:

[0029] (1) Control the pH of the fermentation broth ≤ 5, control the concentration of the long-chain dibasic acid in the fermentation broth to be 5 to 15 wt%, and the density to be 0.9 to 1.16 g / cm 3 , keep the fermentation broth at 92 °C to 103 °C for 10 to 120 min, and after temperature reduction treatment, obtain a first solid-liquid mixture, and the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 to 1000 μm;

[0030] (2) Centrifuge the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture with a long-chain dibasic acid content greater than the content of other solid substances, and a third solid-liquid mixture with a long-chain dibasic acid content less than the long-chain dibasic acid content in the second solid-liquid mixture;

[0031] (3) Separate the long-chain dibasic acid from the second solid-liquid mixture.

[0032] According to some embodiments of the present invention, the temperature of the fermentation broth in step (1) is 30 to 90 °C, such as 35 °C, 40 °C, 45 °C, 48 °C, 50 °C, 55 °C, 57 °C, 60 °C, 62 °C, 65 °C, 68 °C, 70 °C, 75 °C, 80 °C, 85 °C, 88 °C. The temperature of the fermentation broth can be made 30 to 90 °C by heating the fermentation broth.

[0033] According to some embodiments of the present invention, the method comprises the following steps:

[0034] (1) Control the temperature of the fermentation broth to be 30 to 90 °C, the pH of the fermentation broth ≤ 5, control the concentration of the long-chain dibasic acid in the fermentation broth to be 5 to 15 wt%, and the density to be 0.9 to 1.16 g / cm 3 , keep the fermentation broth at 92 °C to 103 °C for 10 to 120 min, after cooling treatment, obtain a first solid-liquid mixture, and the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 50 to 1000 μm;

[0035] (2) Centrifuge the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture with the content of long-chain dibasic acid greater than the content of other solid substances, and a third solid-liquid mixture with the content of long-chain dibasic acid less than the content of long-chain dibasic acid in the second solid-liquid mixture;

[0036] (3) Separate the long-chain dibasic acid from the second solid-liquid mixture.

[0037] For the method described in any one of the present invention, the pH of the fermentation broth in step (1) is 2 to 4.77, further 2 to 4.55, further 2 to 4.5, further 2 to 4.1, further 2 to 4.0, further 2 to 3.9, further 2 to 3.8, further 2 to 3.7, further 2 to 3.45.

[0038] For the method described in any one of the present invention, in step (1), the pH value of the fermentation broth is controlled by acidifying the fermentation broth, and the acids used for acidification include: one or a combination of several of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid and trifluoromethanesulfonic acid.

[0039] For the method described in any one of the present inventions, the starting temperature Tm of the cooling treatment in step (1) is 92°C to 103°C, such as 94°C, 96°C, 98°C, 100°C, 101°C, 102°C. The ending temperature Tn of the cooling treatment in step (1) is 35°C to 85°C, further 45 to 80°C, and even further 60 to 70°C, such as 50°C, 60°C, 70°C, 75°C. The cooling rate of the cooling treatment in step (1) is 0.5 to 20°C / h, such as 3°C / h, 5°C / h, 10°C / h, 11°C / h, 13°C / h, 14°C / h, 15°C / h, 18°C / h, 19°C / h.

[0040] For the method described in any one of the present inventions, the cooling treatment in step (1) includes primary cooling and secondary cooling. The primary cooling rate is 0.5 to 12°C / h, such as 3°C / h, 5°C / h, 10°C / h. The starting temperature of the primary cooling is Tm. The ending temperature T1 of the primary cooling is 85 to 91°C, such as 88°C, 89°C, 90°C. The starting temperature of the secondary cooling is T1. The secondary cooling rate is 5 to 20°C / h, such as 11°C / h, 13°C / h, 14°C / h, 15°C / h, 18°C / h, 19°C / h. The ending temperature of the secondary cooling is Tn.

[0041] Through a suitable cooling process, the crystal particle size of the long-chain dibasic acid can be affected, thereby affecting the separation effect of the long-chain dibasic acid from the thallus and other impurities.

[0042] For the method described in any one of the present inventions, in the first solid-liquid mixture in step (1), the D90 of the long-chain dibasic acid particles is 50 to 1000 μm, further 70 to 800 μm, even further 120 to 800 μm, or 120 to 1000 μm, such as 100 μm, 120 μm, 150 μm, 180 μm, 250 μm, 300 μm, 400 μm, 500 μm, 600 μm, 700 μm. The D50 of the long-chain dibasic acid particles is 30 to 500 μm, further 35 to 400 μm, such as 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 80 μm, 100 μm, 150 μm, 250 μm. The D10 of the long-chain dibasic acid particles is 5 to 25 μm, further 5 to 20 μm, such as 6 μm, 8 μm, 15 μm, 17 μm.

[0043] The term D90: The 90% cumulative volume particle size is a value used to measure the particle size distribution such that 90 vol.% of the crystals have a size lower than this value. The term D50: The 50% cumulative volume particle size is a value used to measure the particle size distribution such that 50 vol.% of the crystals have a size lower than this value. The term D10: The 10% cumulative volume particle size is a value for measuring the particle size of the particle size distribution such that 10 vol.% of the crystals have a size lower than this value.

[0044] For the method described in any one of the present invention, the method for separating the long-chain dibasic acid from the second solid-liquid mixture in step (3) is filtration, which further includes filtration using a plate-and-frame filter press or a chamber filter press.

[0045] According to the method described in any one of the above, it includes the step of drying the separated long-chain dibasic acid.

[0046] According to the method described in any one of the above, it includes the step of washing the separated long-chain dibasic acid with 0.5 to 5 times the weight of water, for example, with 1 time, 3 times, or 4 times the weight of water, and then performing or not performing the drying step.

[0047] According to the method described in any one of the above, it includes the step of adding water to dilute the second solid-liquid mixture before separating the long-chain dibasic acid. For example, water is first added to the second solid-liquid mixture to adjust the concentration of the slurry and then the long-chain dibasic acid is separated by filtration.

[0048] After centrifugation, most of the long-chain dibasic acid particles in the fermentation broth enter the second solid-liquid mixture, i.e., the heavy phase, and most of the bacterial cells enter the third solid-liquid mixture, i.e., the light phase, thereby removing the bacterial cells. Centrifugation affects the separation effect of the long-chain dibasic acid, bacterial cells, and other impurities. Excessive centrifugal force causes the bacterial cells to enter the dibasic acid phase, affecting the separation effect. Before centrifugation, factors such as the particle size, density, or concentration of the fermentation broth can be balanced to further improve the centrifugal separation effect.

[0049] Before centrifugal separation, the temperature of the fermentation broth or the concentration of the long-chain dibasic acid in the fermentation broth can be controlled to further improve the product yield.

[0050] According to the method described in any one of the above, the long-chain dibasic acid includes a saturated or unsaturated straight-chain dibasic acid having 9 to 18 carbon atoms; both ends of the long-chain dibasic acid have carboxyl groups.

[0051] Furthermore, the long-chain dibasic acid includes any one or a combination of several of decanedioic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid. Both ends of the long-chain dibasic acid have carboxyl groups.

[0052] Furthermore, the yield of the long-chain dibasic acid product in this method is more than 95%, such as more than 96%, more than 97%, more than 98%, more than 99%. The purity of the long-chain dibasic acid product obtained by this method is at least more than 95%, such as more than 97%, more than 99%.

[0053] The present invention also claims protection for a long-chain dibasic acid prepared by using the method described in any one of the above.

[0054] Compared with the prior art, the technical effects of the present invention are at least as follows:

[0055] 1. This method is simple to operate, requires less equipment and investment, and has high processing efficiency.

[0056] 2. The fermentation broth is centrifuged and separated under acidic conditions to remove most of the bacteria and impurities.

[0057] 3. This method has a high yield and the obtained product has a high purity. Detailed Embodiments

[0058] The present invention provides a method for effectively separating long-chain dibasic acids from fermentation broth.

[0059] The following terms used herein, unless otherwise specified, have the following meanings.

[0060] In some embodiments, the long-chain dibasic acids include but are not limited to: azelaic acid, sebacic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, octadecanedioic acid and their isomers and derivatives. Both ends of the long-chain dibasic acid have carboxyl groups.

[0061] The term "fermentation broth" means: a liquid system including one or more long-chain dibasic acids. Obtained by using microorganisms to ferment with alkanes, fatty acids and their derivatives as substrates. As long as the microorganisms can oxidize the terminal methyl group of alkanes, fatty acids, and fatty acid derivatives into carboxyl groups to produce long-chain dibasic acids. The microorganisms include, for example, wild-type bacteria or recombinant bacteria, such as Candida.

[0062] In some embodiments, the fermentation broth includes one long-chain dibasic acid; in other embodiments, the fermentation broth includes at least two long-chain dibasic acids.

[0063] In some cases, the bacteria in the fermentation broth are not removed by separate filtration or centrifugation.

[0064] In some cases, the centrifugation can be continuous centrifugation. In some embodiments, the centrifugation uses a centrifuge, including but not limited to a hydrocyclone, a horizontal sedimentation centrifuge (abbreviated as a scroll centrifuge), a siphon scraper centrifuge, or any combination thereof.

[0065] After centrifugation, most of the long-chain dibasic acids enter the second solid-liquid mixture (i.e., the heavy phase after centrifugation), and most of the bacterial cells enter the third solid-liquid mixture (i.e., the light phase after centrifugation) to be separated from the long-chain dibasic acids.

[0066] The long-chain dibasic acids in the second solid-liquid mixture are in solid or particulate form and can be separated or recovered and reused by any conventional solid-liquid separation method in the art, such as filtration separation.

[0067] In some embodiments, the long-chain dibasic acids can be separated by plate-and-frame filtration. In some embodiments, the separated long-chain dibasic acids are dried.

[0068] The method for controlling the concentration of the fermentation broth described in the examples includes dilution or concentration treatments commonly used in the art.

[0069] The method for controlling the density of the fermentation broth described in the examples includes dilution treatment, concentration treatment, or adding inorganic salts or inorganic salt solutions to the fermentation broth. For example, when the density of the fermentation broth to be adjusted is low (Example 6), inorganic salts or solutions of inorganic salts can be added to increase the density of the fermentation broth. The inorganic salts can be, for example, sodium sulfate.

[0070] The low-carbon-number dibasic acids described in Table 1 are dibasic acids with a carbon atom number less than that of the main dibasic acid in the product. For example, the low-carbon-number dibasic acids in the dodecanedioic acid product refer to dibasic acids with a carbon atom number less than or equal to eleven. The low-carbon-number dibasic acids mainly originate from by-products generated during the fermentation process.

[0071] The following embodiments are for further illustration and not for limiting the content claimed in the present invention.

[0072] The test methods in the examples are as follows:

[0073] 1. Gas chromatography detection of dibasic acids: Using a standard dibasic acid sample as a control, referring to GB5413.27-2010 Determination of Fatty Acids in Infant Foods and Dairy Products.

[0074] 2. Bacterial cell recovery rate: Bacterial cell recovery rate (%) = Content of bacterial cells in the third solid-liquid mixture (g) / Content of bacterial cells in the fermentation broth (g) × 100%.

[0075] 3. Recovery rate of long-chain dibasic acids: Recovery rate of long-chain dibasic acids (%) = Weight of long-chain dibasic acid product (g) / Content of long-chain dibasic acids in the fermentation broth (g) × 100%.

[0076] The fermentation broth (DC12 fermentation broth) of dodecanedioic acid in Examples 1 to 7 and Comparative Example 1 and Comparative Example 2 contains 16 wt% of dodecanedioic acid and 1 wt% of bacterial cells. Provided by Kaisai (Jinxiang) Biomaterials Co., Ltd.

[0077] Example 1

[0078] Heat the fermentation broth of dodecanedioic acid to 62 °C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, then control the concentration of dodecanedioic acid in the fermentation broth to 10 wt%, and control the density of the fermentation broth at 1.05 g / cm 3 .

[0079] Keep the above fermentation broth at 102 °C for 60 min, then cool it to 90 °C at a rate of 8 °C / h, and then cool it to 60 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. Test the particle size distribution of dodecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0080] Centrifuge the first solid-liquid mixture with a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2000 rpm.

[0081] The obtained second solid-liquid mixture is filtered and separated with a plate and frame filter press to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain a dodecanedioic acid product.

[0082] Example 2

[0083] Heat the fermentation broth of dodecanedioic acid to 62 °C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, then control the concentration of dodecanedioic acid in the fermentation broth to 10 wt%, and control the density of the fermentation broth at 1.05 g / cm 3 .

[0084] Keep the above fermentation broth at 102 °C for 60 min, then cool it to 90 °C at a rate of 8 °C / h, and then cool it to 60 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. Test the particle size distribution of dodecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0085] Centrifuge the first solid-liquid mixture with a horizontal screw centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the horizontal screw centrifuge is 2500 rpm.

[0086] The obtained second solid-liquid mixture is filtered and separated with a plate and frame filter press to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water and dried to obtain a dodecanedioic acid product.

[0087] Example 3

[0088] Heat the fermentation broth of dodecanedioic acid to 62 °C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, then control the concentration of dodecanedioic acid in the fermentation broth to 10 wt%, and control the density of the fermentation broth at 1.05 g / cm 3 .

[0089] Keep the above fermentation broth at 102 °C for 10 min, then cool it to 90 °C at a rate of 8 °C / h, and then cool it to 60 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. Test the particle size distribution of dodecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0090] Centrifuge the first solid-liquid mixture with a horizontal spiral centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the horizontal spiral centrifuge is 2000 rpm.

[0091] The obtained second solid-liquid mixture is filtered and separated with a plate and frame filter press to obtain dodecanedioic acid, then wash the dodecanedioic acid with 2 times the mass of water, and dry it to obtain the dodecanedioic acid product.

[0092] Example 4

[0093] Heat the fermentation broth of dodecanedioic acid to 62 °C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, then control the concentration of dodecanedioic acid in the fermentation broth to 8 wt%, and control the density of the fermentation broth at 1.00 g / cm 3 .

[0094] Keep the above fermentation broth at 102 °C for 60 min, then cool it to 90 °C at a rate of 8 °C / h, and then cool it to 60 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. Test the particle size distribution of dodecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0095] Centrifuge the first solid-liquid mixture with a horizontal spiral centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the horizontal spiral centrifuge is 2000 rpm.

[0096] The obtained second solid-liquid mixture is filtered and separated with a plate and frame filter press to obtain dodecanedioic acid, then wash the dodecanedioic acid with 2 times the mass of water, and dry it to obtain the dodecanedioic acid product.

[0097] Example 5

[0098] Heat the fermentation broth of dodecanedioic acid to 62 °C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, then control the concentration of dodecanedioic acid in the fermentation broth to 6 wt%, and control the density of the fermentation broth at 0.95 g / cm3 。

[0099] The above fermentation broth was kept at 102 °C for 60 min, then cooled to 90 °C at a rate of 8 °C / h, and subsequently cooled to 85 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid in the first solid-liquid mixture was measured, and the test results are shown in Table 1.

[0100] The first solid-liquid mixture was centrifuged by a horizontal scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the horizontal scroll centrifuge was 2000 rpm.

[0101] The obtained second solid-liquid mixture was filtered and separated by a plate and frame filter press to obtain dodecanedioic acid, and then the dodecanedioic acid was washed with 2 times the mass of water and dried to obtain a dodecanedioic acid product.

[0102] Example 6

[0103] The fermentation broth of dodecanedioic acid was heated to 62 °C, and a 3.5 mol / L sulfuric acid solution was added to the above fermentation broth to adjust the pH of the fermentation broth to 3.5. Then, the concentration of dodecanedioic acid in the fermentation broth was controlled to be 3 wt%, and the density of the fermentation broth was controlled at 1.15 g / cm 3 。

[0104] The above fermentation broth was kept at 102 °C for 60 min, then cooled to 90 °C at a rate of 8 °C / h, and subsequently cooled to 60 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. The particle size distribution of dodecanedioic acid in the first solid-liquid mixture was measured, and the test results are shown in Table 1.

[0105] The first solid-liquid mixture was centrifuged by a horizontal scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the horizontal scroll centrifuge was 2000 rpm.

[0106] The obtained second solid-liquid mixture was filtered and separated by a plate and frame filter press to obtain dodecanedioic acid, and then the dodecanedioic acid was washed with 2 times the mass of water and dried to obtain a dodecanedioic acid product.

[0107] Example 7

[0108] The fermentation broth of dodecanedioic acid was heated to 62 °C, and a 3.5 mol / L sulfuric acid solution was added to the above fermentation broth to adjust the pH of the fermentation broth to 4.7. Then, the concentration of dodecanedioic acid in the fermentation broth was controlled to be 10 wt%, and the density of the fermentation broth was controlled at 1.05 g / cm 3 。

[0109] Keep the above fermentation broth at 85°C for 60 min, and then cool it to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. Test the particle size distribution of dodecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0110] Centrifuge the first solid-liquid mixture through a scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the scroll centrifuge is 2000 rpm.

[0111] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter press to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water, and dried to obtain a dodecanedioic acid product.

[0112] Comparative Example 1

[0113] Heat the fermentation broth of dodecanedioic acid to 62°C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, and then control the concentration of dodecanedioic acid in the fermentation broth to be 16 wt%, and control the density of the fermentation broth at 1.05 g / cm 3 .

[0114] Keep the above fermentation broth at 102°C for 60 min, and then cool it to 90°C at a rate of 8°C / h, and then cool it to 25°C at a rate of 16°C / h to obtain a first solid-liquid mixture. Test the particle size distribution of dodecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0115] Centrifuge the first solid-liquid mixture through a scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the scroll centrifuge is 2000 rpm.

[0116] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter press to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water, and dried to obtain a dodecanedioic acid product.

[0117] Comparative Example 2

[0118] Heat the fermentation broth of dodecanedioic acid to 62°C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 1.5, and then control the concentration of dodecanedioic acid in the fermentation broth to be 10 wt%, and control the density of the fermentation broth at 1.06 g / cm 3 .

[0119] Keep the above fermentation broth at 102°C for 10 min, and then cool it to 90°C at a rate of 8°C / h, and then cool it to 60°C at a rate of 16°C / h to obtain a first solid-liquid mixture. Test the particle size distribution of dodecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0120] The first solid-liquid mixture is centrifuged by a horizontal scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the horizontal scroll centrifuge is 500 rpm.

[0121] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter press to obtain dodecanedioic acid, and then the dodecanedioic acid is washed with 2 times the mass of water, and the dodecanedioic acid product is obtained after drying.

[0122] Comparative Example 3

[0123] The fermentation broth of △9-1,18-octadecene dicarboxylic acid contains 10 wt% of dodecanedioic acid and 1 wt% of bacterial cells. The above fermentation broth is heated to 62 °C, and a 3.5 mol / L sulfuric acid solution is added to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of △9-1,18-octadecene dicarboxylic acid in the fermentation broth is controlled to be 8 wt%, and the density of the fermentation broth is controlled at 1.05 g / cm 3 。

[0124] The above fermentation broth is kept at 100 °C for 60 min, then cooled to 90 °C at a rate of 8 °C / h, and then cooled to 60 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. The particle size distribution of △9-1,18-octadecene dicarboxylic acid in the first solid-liquid mixture is tested, and the test results are shown in Table 1.

[0125] The first solid-liquid mixture is centrifuged by a horizontal scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the horizontal scroll centrifuge is 2000 rpm.

[0126] The obtained second solid-liquid mixture is filtered and separated by a plate-and-frame filter press to obtain △9-1,18-octadecene dicarboxylic acid, and then the △9-1,18-octadecene dicarboxylic acid is washed with 2 times the mass of water, and the △9-1,18-octadecene dicarboxylic acid product is obtained after drying.

[0127] Comparative Example 4

[0128] It is basically the same as Comparative Example 3, and the only difference is that: in this Comparative Example 4, the drum speed of the horizontal scroll centrifuge is 3200 rpm.

[0129] Example 8

[0130] The fermentation broth of undecanedioic acid (DC11 fermentation broth, Kaisai (Jinxiang) Biomaterials Co., Ltd.) contains 15 wt% of undecanedioic acid and 1 wt% of bacterial cells. The above fermentation broth is heated to 62 °C, and a 3.5 mol / L sulfuric acid solution is added to the above fermentation broth to adjust the pH of the fermentation broth to 3.5, and then the concentration of undecanedioic acid in the fermentation broth is controlled to be 10 wt%, and the density of the fermentation broth is controlled at 1.02 g / cm 3 。

[0131] Keep the above fermentation broth at 92 °C for 60 min, then cool it to 88 °C at a rate of 8 °C / h, and subsequently cool it to 45 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. Test the particle size distribution of undecanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0132] Centrifuge the first solid-liquid mixture through a scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the scroll centrifuge is 2000 rpm.

[0133] The obtained second solid-liquid mixture is filtered and separated by a plate and frame filter press to obtain undecanedioic acid, and then the undecanedioic acid is washed with 2 times the mass of water and dried to obtain an undecanedioic acid product.

[0134] Example 9

[0135] The fermentation broth of decanedioic acid (DC10 fermentation broth, Kaisai (Jinxiang) Biomaterials Co., Ltd.), contains 12 wt% of decanedioic acid and 1.2 wt% of bacteria. Heat the above fermentation broth to 62 °C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 3.8, then control the concentration of decanedioic acid in the fermentation broth to 8 wt%, and control the density of the fermentation broth at 0.92 g / cm 3 。

[0136] Keep the above fermentation broth at 100 °C for 50 min, then cool it to 89 °C at a rate of 8 °C / h, and subsequently cool it to 50 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. Test the particle size distribution of decanedioic acid in the first solid-liquid mixture, and the test results are shown in Table 1.

[0137] Centrifuge the first solid-liquid mixture through a scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture. The drum speed of the scroll centrifuge is 2300 rpm.

[0138] The obtained second solid-liquid mixture is filtered and separated by a plate and frame filter press to obtain decanedioic acid, and then the decanedioic acid is washed with 2 times the mass of water and dried to obtain a decanedioic acid product.

[0139] Example 10

[0140] The fermentation broth of hexadecanedioic acid (DC16 fermentation broth, Kaisai (Jinxiang) Biomaterials Co., Ltd.), contains 9 wt% of hexadecanedioic acid and 0.8 wt% of bacteria. Heat the above fermentation broth to 62 °C, add a 3.5 mol / L sulfuric acid solution to the above fermentation broth to adjust the pH of the fermentation broth to 4, then control the concentration of hexadecanedioic acid in the fermentation broth to 6 wt%, and control the density of the fermentation broth at 1.05 g / cm 3 。

[0141] The above fermentation broth is kept at 101 °C for 80 min, then cooled to 90 °C at a rate of 8 °C / h, and subsequently cooled to 80 °C at a rate of 16 °C / h to obtain a first solid-liquid mixture. The particle size distribution of the hexadecane diacid in the first solid-liquid mixture is tested, and the test results are shown in Table 1.

[0142] The first solid-liquid mixture is centrifuged by a scroll centrifuge to obtain a second solid-liquid mixture and a third solid-liquid mixture, and the drum speed of the scroll centrifuge is 2100 rpm.

[0143] The obtained second solid-liquid mixture is filtered and separated by a plate and frame filter press to obtain hexadecane diacid, and then the hexadecane diacid is washed with water having a mass twice that of the hexadecane diacid, and after drying, a hexadecane diacid product is obtained.

[0144] Table 1 Test result table of each index

[0145]

[0146] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method for extracting long-chain dibasic acids from a fermentation broth, the method comprises the following steps: (1) Control the pH of the fermentation broth to be 2 to 5 and the density to be 0.9 to 1.16 g / cm 3 , and after cooling treatment, a first solid-liquid mixture is obtained, and the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 120 to 1000 μm; (2) Centrifuge the first solid-liquid mixture in step (1) to obtain a second solid-liquid mixture with a long-chain dibasic acid content greater than that of other solid substances, and a third solid-liquid mixture with a long-chain dibasic acid content less than that in the second solid-liquid mixture; (3) Separate the long-chain dibasic acids from the second solid-liquid mixture; wherein, the concentration of the long-chain dibasic acids in the fermentation broth is controlled to be 6-15 wt%; The starting temperature Tm of the temperature reduction treatment in step (1) is 92°C - 103°C, and the ending temperature Tn is 35°C - 85°C; before the temperature reduction treatment in step (1), the fermentation broth is kept at 92°C - 103°C for 10 - 120 min; the temperature reduction treatment includes primary temperature reduction and secondary temperature reduction, the rate of the primary temperature reduction is 0.5 - 12°C / h; the starting temperature T1 of the secondary temperature reduction is 85 - 91°C, and the rate of the secondary temperature reduction is 5 - 20°C / h.

2. The method according to claim 1, characterized in that: the concentration of the long-chain dibasic acids in the fermentation broth is controlled to be 6-12 wt%; and / or, the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 120 - 800 μm; and / or, the rotation speed of the centrifugation is 1500 - 2900 rpm; and / or, before the temperature reduction treatment in step (1), the fermentation broth is kept at 92°C - 103°C for 20 - 120 min.

3. The method according to claim 1, characterized in that: the recovery rate of the thalli in the third solid-liquid mixture is 90 - 95%; and / or, the content of the long-chain dibasic acids in the second solid-liquid mixture ≥ 40 wt%; and / or, the D90 of the long-chain dibasic acid particles in the first solid-liquid mixture is 180 - 800 μm; and / or, the D50 of the long-chain dibasic acid particles in the first solid-liquid mixture is 30 - 500 μm; and / or, the D10 of the long-chain dibasic acid particles in the first solid-liquid mixture is 5 - 25 μm; and / or, before the temperature reduction treatment in step (1), the fermentation broth is kept at 92°C - 103°C for 30 - 90 min.

4. The method according to claim 1, characterized in that: the content of the long-chain dibasic acids in the second solid-liquid mixture is 40 - 70 wt%; and / or, the D50 of the long-chain dibasic acid particles in the first solid-liquid mixture is 35 - 400 μm; and / or, the D10 of the long-chain dibasic acid particles in the first solid-liquid mixture is 5 - 20 μm; and / or, before the temperature reduction treatment in step (1), the fermentation broth is kept at 92°C - 103°C for 50 - 60 min.

5. The method according to claim 1, characterized in that: the equipment for centrifugation includes a hydrocyclone, a horizontal sedimentation centrifuge, a siphon scraper centrifuge, or any combination thereof; and / or, the ending temperature Tn of the temperature reduction treatment in step (1) is 60 - 70°C.

6. The method according to claim 5, characterized in that: The centrifugal equipment is a horizontal sedimentation centrifuge, and the rotational speed of the drum is 1500 - 2900 rpm; and / or, The starting temperature of the first-stage cooling is Tm; and / or, the ending temperature T1 of the first-stage cooling is 85 - 91 °C; and / or, the ending temperature of the second-stage cooling is Tn.

7. According to the method described in claim 1, it is characterized in that: The ending temperature Tn of the cooling treatment in step (1) is 45 - 80 °C; And / or, controlling the density of the fermentation broth to be 0.98 to 1.06 g / cm 3 .

8. According to the method described in claim 1, it is characterized in that: The temperature of the fermentation broth in step (1) is 30 - 90 °C; and / or, the pH of the fermentation broth in step (1) is 2 - 4.77; and / or, in step (1), the pH value of the fermentation broth is controlled by acidifying the fermentation broth, and the acids used for acidification include one or a combination of several of sulfuric acid, hydrochloric acid, nitric acid, acetic acid, phosphoric acid, and trifluoromethanesulfonic acid; and / or, The pH of the fermentation broth in step (1) is 2 - 4.55, further 2 - 4.5, still further 2 - 4.1, still further 2 - 4.0, still further 2 - 3.9, still further 2 - 3.8, still further 2 - 3.7, still further 2 - 3.

45.

9. According to the method described in claim 1, it is characterized in that: The method for separating the long-chain dibasic acid from the second solid-liquid mixture in step (3) is filtration; and / or, it includes the step of washing the separated long-chain dibasic acid with 0.5 - 5 times the weight of water, and then drying or not drying; and / or, it includes the step of adding water to dilute the second solid-liquid mixture before separating the long-chain dibasic acid; and / or, it includes the step of drying the separated long-chain dibasic acid; and / or, the long-chain dibasic acid includes a saturated or unsaturated straight-chain dibasic acid with 9 - 18 carbon atoms; both ends of the long-chain dibasic acid have carboxyl groups.

10. According to the method described in claim 9, it is characterized in that: A plate and frame filter press or a chamber filter press is used for the filtration in step (3).

11. According to the method described in claim 1 or 2 or 3 or 4 or 9, it is characterized in that: The long-chain dibasic acid includes any one or a combination of several of decanedioic acid, undecanedioic acid, dodecanedioic acid, tridecanedioic acid, tetradecanedioic acid, pentadecanedioic acid, hexadecanedioic acid, heptadecanedioic acid, and octadecanedioic acid.

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